Chapter 14 Flashcards
First level of defense
Barriers that block the pathogen at the portal of entry.
Anatomical structures
Skin, mucous membranes, cilia
Chemical barriers
Fatty acids, lysozyme (tears/saliva), gastric acidity
Second level of defense
Includes generalized protective cells and fluids in tissues (phagocytes)
Third level of defense
includes specific immune reactions with microbes that are required for survival (lymphocytes and antibodies)
Immunity
specific resistance aquired to an infectious agent
Components of immunity
a diffuse network of cells, fibers, chemicals, fluids, tissues, and organs that permeate the human body
Reticuloendothelial (mononuclear phagocyte) system
Continuous network of fibers and phagocytes that surrounds tissues and organs
Extracellular fluid
a fluid environment in which all cells are bathed
lymphatic system
a series of vessels and organs that carry lymph from tissues
blood stream
circulates blood to all organs
Composition of whole blood
55% plasma and 45% formed elements
Plasma
a clear liquid that contains nutrients, ions, gases, hormones, antibodies, albumin, and waste products dissolved in water
The cell-free, fluid portion of blood, which contains all the clotting factors
Serum
Plasma minus the clotting factors
Blood cells are formed by ______ in particular ______ sites
hemopoiesis, bone marrow
The 3 main lines of cells that come from stem cells
- leukocytes (WBC)
- erythrocytes (RBC)
- Megakaryocytes – platelets
Erythrocytes
biconcave sacs of hemoglobin that transport oxygen to and from the tissues
Have no mitochondria and lose nuclei
What is the stain used for RBC?
Wright stain - shows small pink circles
Explain the relationship of RBC and the immune system
They have no immune functions but they are the target of the immune reactions
Describe the path from Stem Cell to RBC
Stem cell -> erythrocyte line -> erythroblast -> normoblast -> reticulocyte -> Erythrocyte (RBC)
1 cause of death
respiratory tract infections
What is a mast cell?
a cell found within connective tissue that contains heparin and histamine. These substances are released from the mast cell in response to injury and infection.
Platelets are also known as _____
thrombocytes
Describe path from Stem cell to platelet
Stemcell, megakaryocyte, thrombocyte (platelet)
Describe thrombocytes
(aka platelets) pieces of cells that come from bone marrow. They are small in size.
Come from bone marrow as megakaryocyte which disintegrates into bits of cytoplasm and nuclus
How many platelets in blood?
250,000 - 500,000/mm3 of blood
Three granular leukocytes.
Basophils, eosinophils, and neutrophils
Agranular leukocytes
monocytes and lymphocytes
Function of platelets
Hemostasis
Hemostasis
plugging broken blood vessles to stop bleeding
Inflammatory response
This complex system responds to tissue injury (infection, burn, allergy) by movilizing the immune system against pathogens, repairing damage, and clearing infection.
Signs and symptoms of inflammatory response
redness, heat, swelling, pain
Blood vessels narrow and dialate in response to ______ released by ________ and ___________
chemical mediators (cytokines), injured tissues and WBCs
What will keep the infection from spreading and swell the tissues? (inflammatory response)
build up of fluid from edema
mediators attract _________ to engluf _______ and _______
neutrophils, debris, and microbes
What types of items will collect in pus?
WBCs, microbes, debris, and fluid
_____ clean up the residue of inflammation
macrophages
what doe lymphocytes do during inflammatory response?
carry out immune reactions such as antibody formation and healing occurs
Long term inflammation can result in
injury and disease (granuloma)
Fever is due to ______
pyrogens
What are pyrogens?
substances released by certain white blood cells that alter the temperature setting of the brain
Effects of fever…
slow microbial multiplication and stimulate the immune response
Phagocytosis
a process whereby foreign materials are engulfed and destroyed
Neutrophils
engluf small particles, microbes, molecules, etc
Macrophages
- Larger cells that scavenge large pockets of cellular debris and extract antigentic information
Where are macrophages found
in specific tissue or organ (liver, lung, skin) or are free and wandering
What happens after materials are engulfed by the cell into a phagosome vacuole?
lysosomes containing powerful chemicals unite with the phagosome and destroy contents
The primary cells of host defense and immunity can be classified as
granulocytes and agranulocytes
Granulocytes
Basophils, eosinophils, and neutrophils
polymorpho nuclear leukocytes
contain distinct granules in cytoplasm
Agranulocytes
Monocytes and lymphocytes
mononuclear lymphocytes
Lack noticeable granules
have globular, non-lobed nuclei
Neutrophils
Function as phagocytes… important in phagocytosis
55-90% of the blood stream (25x10^9 in avg body) is made of which type of blood cell?
Neutrophils
Has a horseshoe - shaped nucleus
Nuetrophils
Neutrophils contain _____ ______ and other chemicals to degrade phagocytized materials
digestive enzymes
Eosinophils
function in worm and fungal infections… Role is not completely understood
Scarcest leukocyte
basophils (less than .5%)
1 - 3% of blood stream
eosinophils
eosinophils are found mostly in the
spleen
The Wright stain is used to easily distinguish
Eosinophils (orange - red)
The granules of eosinophils contain
peroxidase, lysozyme, and other digestive enzymes
Eosinophils have weak action on _________ and strong action on ________
bacteria, virus, etc.
parasites and fungi (eukaryotic cells)
Blood cell involved in allergic reactions and inflammation
basophils
Stains for basophils
acidic dyes (eosin) and basic dyes (methylene blue)
Basophils work with _________ and are similar to ____________
tissue mast cells … non-motile mast cells
Basophils release
histamine, serotonin, heparin, and several enzymes
How do lymphocytes move?
ameboid motion
20 - 30% of leukocytes in blood
lymphocytes
Lymphocytes are most important in
immunological functions
Diapedesis
how WBCs (lymphocytes) move from blood to tissue between endothelial cells of small blood vessels. They extrude bw spaces into extracellular regions because they have a “plastic shape”
How do lymphocytes respond to tissue injury or infection?
by migrating toward chemical signals (chemotaxis)
B and T cells are generated by
lymphocytes
B-cells are from the
chicken glad (Bursa of Fabricious) and human bone marrow
T-cells are from the
thymus
B-cells are involved in
humural activity
humural activity
protective molecules carried in the fluids of the body
Describe path of B-cell to antibody
B-cell > activated B cell > plasma cell > antibody (protein)
T-cells engage in many immune reactions collectively called
cell-mediated immunity (CMI)
Types of T-cells
Suppress, help, and kill
Largest leukocyte
monocyte
Percentage of monocytes as phagocytes in blood stream
3-7%
Describe the morphology of the nucleus in a monocyte
oval or kidney shaped
Monocytes
Have vacuoles with digestive enzymes
start as phagocytes (small) then macrophages
Long lived and multiplies
Which blood cell cleans systems of debris
monocytes
Monocytes transport …
foreign molecules to lymphocytes
Monocytes secrete compounds that …
assist, mediate, attract, and inhibit immune cells and reactions
The lymphatic system
it begins as fine capillaries in tissues and gradually joins together with larger vessels that eventually drain into the blood circulation
Lymph
fluid that contains serum components of WBC (vessels transport lymph)
thick yellow fluid carried by lymphatic circulation
Made of: water, dissolved salts, and 2-5% protein
Transports: wbc, fats, cellular debris, infectious agents (microorgs) NO RBCs
Lymphatic organs
lymph nodes, spleen, thymus, tonsils, gut-associated lymphoid tissue (GALT), Peyer’s patches
Lymph nodes
compact filters where lymphocytes aggregate and where immune challenges occur
Spleen
blood filter and respository of immune cells
thymus
where t-cells mature
Lymphatic vessels
transport lymph along the lines of regular blood vessels
Unidirectional: from extremities to heart
Complement C-Factor
a complex, multiple duty, versatile back up system of the immune system
Chemical defense system that destroys certain pathogens and produces chemical mediators
complement c-factor
The complement c-factor completes or brushes up
immune reaction
The complement c-factor is made of _______ that work together to ____________
20 blood proteins
destroy microorgs invading our system
Complement c-factor will attack ______
membranes of bacteria
The system components of C-Factor come from ______
liver hepatocytes, lymphocytes, and monocytes
C-factor focuses on
speed, activity, and efficacy of action
Comlement involves chemical (c-factors) that act in a __________
cascade fashion
Cascade reaction
sequential physiological response, in which the first substance in a chemical series activates the next substance, which activates the next, and so on until a desired end product is reached
C1 –> C9
Pathways of cascade reaction
classical and alternate
Classical pathway
activation of C by specific Antibody
Alternate pathway
non-specific reaction to infections
results in the Membrane Attack Complex (MAC)
Membrane Attack Complex (MAC)
destroys all kinds of microorgs by disrupting their cell membranes
What is an interferon (IFN)?
a small protein produced by certain WBCs and tissue cells. Used as therapy against certain viral infections and cancer and other microbes. Not virus specific. Deals with immune regulation and intercommunication
Types of interferons
alpha, beta, and gamma - interferons
The types of interferons are produced in response to
viruses, RNA, immune products, and various agents
Alpha-interferon
product of lymphocytes and macrophages
activates natural killer cells
stimulates phagocytes
Beta-interferon
From fibroblast and epithelial cells
Role in maturation of B and T cells
stimulate phagocytes
Gamma-interferon
product of T-cells
immune regulator of macrophages, B&T cells
inhibits some cancer cells
Interferons bind to _________ and induce changes in ___________ and thus results vary
cell surfaces; genetic expression
All 3 types of interferons can inhibit _____ and have _______
expression of cancer genes; tumor suppressor effects
Specificity
Ab against chicken pox will function against that particular virus only
Memory
lymphocytes recall their first engagement with the invader (ag) and rush to attack once again
Antigen (Immunogens)
proteins or other complex molecules of high MW that trigger the immune response in the host. Generate production of antibodies
Immunocompetence develops during
late fetal or early neonatal period when b&t cells react to only one spec antigen
B&T cells generate
aquired specific immunities
